tinyusdz/tests/usda/usdlux_mesh_lights_simple.usda

#usda 1.0
(
    doc = "Simple MeshLightAPI test - Emissive geometry as light sources"
    defaultPrim = "World"
    metersPerUnit = 1
    upAxis = "Y"
)

def Xform "World"
{
    def Scope "Lights"
    {
        # Simple emissive cube (mesh light)
        def Mesh "EmissiveCube" (
            apiSchemas = ["MeshLightAPI"]
        )
        {
            int[] faceVertexCounts = [4, 4, 4, 4, 4, 4]
            int[] faceVertexIndices = [
                0, 1, 3, 2,  # Front
                4, 5, 7, 6,  # Back
                0, 4, 6, 2,  # Left
                1, 5, 7, 3,  # Right
                0, 1, 5, 4,  # Bottom
                2, 3, 7, 6   # Top
            ]
            point3f[] points = [
                (-0.5, -0.5, -0.5), (0.5, -0.5, -0.5),  # Bottom
                (-0.5, 0.5, -0.5), (0.5, 0.5, -0.5),    # Top front
                (-0.5, -0.5, 0.5), (0.5, -0.5, 0.5),    # Bottom back
                (-0.5, 0.5, 0.5), (0.5, 0.5, 0.5)       # Top back
            ]

            # MeshLightAPI properties
            float inputs:intensity = 50.0
            color3f inputs:color = (1.0, 0.8, 0.6)
            bool inputs:normalize = true

            double3 xformOp:translate = (0, 2, 0)
            uniform token[] xformOpOrder = ["xformOp:translate"]
        }

        # Emissive rectangle (simple quad mesh light)
        def Mesh "LightPanel" (
            apiSchemas = ["MeshLightAPI"]
        )
        {
            int[] faceVertexCounts = [4]
            int[] faceVertexIndices = [0, 1, 2, 3]
            point3f[] points = [
                (-1.0, 0, -0.5),
                (1.0, 0, -0.5),
                (1.0, 0, 0.5),
                (-1.0, 0, 0.5)
            ]
            normal3f[] normals = [
                (0, -1, 0), (0, -1, 0), (0, -1, 0), (0, -1, 0)
            ] (
                interpolation = "vertex"
            )

            # MeshLightAPI properties
            float inputs:intensity = 100.0
            color3f inputs:color = (0.9, 0.95, 1.0)
            bool inputs:normalize = false

            # Material sync mode
            token inputs:materialSyncMode = "independent"

            double3 xformOp:translate = (0, 3.5, 0)
            uniform token[] xformOpOrder = ["xformOp:translate"]
        }

        # Standard sphere light for comparison
        def SphereLight "StandardLight"
        {
            color3f inputs:color = (1.0, 1.0, 1.0)
            float inputs:intensity = 75.0
            float inputs:radius = 0.3

            double3 xformOp:translate = (-3, 2, 2)
            uniform token[] xformOpOrder = ["xformOp:translate"]
        }
    }

    # Reference geometry
    def Xform "Scene"
    {
        def Sphere "TestSphere"
        {
            double radius = 0.8
            double3 xformOp:translate = (0, 0.8, 0)
            uniform token[] xformOpOrder = ["xformOp:translate"]
        }

        def Mesh "Floor"
        {
            int[] faceVertexCounts = [4]
            int[] faceVertexIndices = [0, 1, 2, 3]
            point3f[] points = [
                (-5, 0, -5), (5, 0, -5), (5, 0, 5), (-5, 0, 5)
            ]
            normal3f[] normals = [
                (0, 1, 0), (0, 1, 0), (0, 1, 0), (0, 1, 0)
            ] (
                interpolation = "vertex"
            )
        }
    }
}